Low R I, Takeda P, Mason D T, DeMaria A N
Am J Cardiol. 1982 Feb 18;49(3):547-53. doi: 10.1016/s0002-9149(82)80010-6.
The hemodynamic effects of calcium blocking agents are a composite of the various direct and indirect cardiac and peripheral vascular actions of these drugs on the individual determinants of left ventricular pump function. Calcium antagonists have been shown to have a direct negative inotropic effect, a direct negative chronotropic effect and a direct effect to produce relaxation of vascular smooth muscle and vasodilation. These agents may also elicit important indirect effects by an anti-ischemic action referable to both coronary arterial dilation and reduction in myocardial oxygen demand, as well as a baroreceptor-mediated reflex increase in beta adrenergic tone in response to vasodilation. The net result of these direct and indirect actions on cardiocirculatory dynamics is also dependent upon the individual calcium blocking agent administered, the dose and route of administration, and the underlying status of left ventricular function. Available data do not lead to a clear definition of the hemodynamic effects referable to calcium blocking agents that may be produced by the interaction of all variable factors. At present, however, it would appear that the direct negative inotropic and chronotropic actions of the calcium antagonists are offset by the reflex increase in beta adrenergic tone, in combination with the reduction in afterload produced by the peripheral vascular effects of these agents. Preliminary data suggest that certain calcium inhibiting agents may be useful in the vasodilator therapy of congestive heart failure. Nevertheless, the direct negative inotropic effects of these agents have resulted in clinically evident decompensation in cardiac performance in patients with advanced left ventricular dysfunction, and caution is warranted in the application of calcium blocking agents in this setting.
钙通道阻滞剂的血流动力学效应是这些药物对左心室泵功能各个决定因素的多种直接和间接心脏及外周血管作用的综合表现。钙拮抗剂已被证明具有直接的负性肌力作用、直接的负性变时作用以及使血管平滑肌松弛和血管扩张的直接作用。这些药物还可能通过抗缺血作用引发重要的间接效应，这既归因于冠状动脉扩张和心肌需氧量减少，也归因于压力感受器介导的反射性β肾上腺素能张力增加以应对血管扩张。这些直接和间接作用对心脏循环动力学的最终结果还取决于所使用的具体钙通道阻滞剂、给药剂量和途径以及左心室功能的基础状态。现有数据无法明确界定所有可变因素相互作用可能产生的钙通道阻滞剂的血流动力学效应。然而，目前看来，钙拮抗剂的直接负性肌力和负性变时作用被β肾上腺素能张力的反射性增加以及这些药物外周血管效应导致的后负荷降低所抵消。初步数据表明，某些钙抑制剂可能对充血性心力衰竭的血管扩张治疗有用。尽管如此，这些药物的直接负性肌力作用已导致晚期左心室功能不全患者出现临床上明显的心脏功能失代偿，因此在这种情况下应用钙通道阻滞剂时应谨慎。
